Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds meaningful behavioral guarantees: results are grouped by UTC day, limited to 31 days, and intentionally exclude appointment identifiers, times, and all clinical fields, which is not visible in the schema or annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no filler; the core behavior is front-loaded and the privacy/data-scope caveat is placed immediately after. Every clause adds information an agent needs before calling the tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only aggregate tool with a rich output schema, full parameter documentation, and strong annotations, the description covers purpose, scope, constraints, and output limitations. Nothing essential is missing for correct tool selection and invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description adds value beyond the schema by explaining the effective date-range limit (at most 31 days), the UTC-day aggregation unit, and that clinicId must identify a tenant-owned single clinic.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description opens with a specific verb and resource: 'Count scheduled records by UTC day' for a single clinic, with a hard 31-day cap. The 'aggregate administrative counts only' clause clearly separates it from detail-returning siblings like list_calendar_events or get_clinic_availability.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context: use it for aggregate administrative counts over a date range, scoped to one tenant-owned clinic. It does not explicitly name alternative tools or state when not to use it, but the 'never... clinical data' exclusion effectively prevents misuse for detailed schedule or clinical queries.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.